Holly, the biggest leaf on Blue Hawaii is 28in. long. It's growing a new leaf about every 4 days, too. Drinks like a sailor, though, I'm watering it twice a day when it doesn't rain.
I just moved it up into this corner by the pool where it gets morning sun, and is shaded all afternoon so maybe that will slow it down enough that I don't have to re-pot it again, It's been in that 18in. pot for less than a month and already looking like it could use more room . . .